The present invention relates to the manufacture of integrated circuit devices, and more specifically, to controlling threshold voltage of transistors by using a blanket short channel rollup implant combined with a non-angled long channel compensating implant.
In order to increase integrated circuit device performance, it is often desirable to lower the threshold voltage required to make transistors switch from one state to another state. Various implants are utilized in order to lower the threshold voltage of transistors. For example, one common implant is known as a “halo” implant and is created by performing angled implants of dopant species to drive the impurity beneath the gate conductor stack of the transistor.
However, as the size of transistors is reduced and as the density and pitch of transistors is increased (along with the utilization of relatively tall structures such as fin-type field effect transistors (FinFETs)) it becomes more and more difficult to perform angled implants that can reduce threshold voltage by a meaningful amount.